Resistance



" M h 1935- M. w. WEISCOPF RESISTANCE Filed Dec. 19, 1950 BY ATTORNEYS INVENTOi? Marcus W TVeisc Patented Mar. 5, 1935 i UNITED STATES PATENT OFFICE RESISTANCE Marcus W. Weiscopf, Philadelphia, Pa, assignor to International Resistance Company, Philadelphia, Pa., a corporation of Delaware Application December 19, 1930, Serial No. 503,440

17 Claims. (Cl, 201-63) The inventionrelates to resistors and mount- Figure 8 isa side elevation of a mold for forms therefor. ing the mounting for the resistors, with the re One of the objects of the invention is to prosistors in position in the mold shown in cross vide a resistor having internal connections which section, and are "noiseless in an audio circuit. Another ob Figure 9 is a sectional view taken on the line 5 ject of the invention is to provide a construction 9-9 of Figure 8. for the terminals-of resistors which is extremely Similar reference characters refer to similar durable and which lends itself to manufacture in parts throughout the several views of the draw-. quantities at low cost. Another object of the ing.

10 invention is to provide an efiicient method of at- Referring first to Figures 1 and 2, the resistor, in taching together a plurality of resistors in gang indicated generally by the numeral 10, preferaformation. Another object of the invention is to bly consists of a rod or bar of porcelain or other provide a resistor gang unit adapted for attachinsulating substance 11 having a capillary pasment to another gang unit. Another object of sage 12 through which extends a resistance cont invention is to p ovide a practical resistor ductor 13 embedded in metal end pieces 14, 1e. 15 gang construction which is rigid and durable. The resistance conductor 13 preferably comprises Another j ct 0f e i vention is to provide a a glass rod or filament covered with a conductive resistor gang construction which is, for practical coating of high resistance material, such as carp rposes, a unit. Another object of the invenbon. The conductor 13 is in intimate contact tion is to provide a mounting for resistors adaptwith the wall of the capillary passage 12, the 20 ed to act as a ground for one or more of them. diameter of the conductor being preferably as other O j Will be in P Obvious in Da near to the diameter of the capillary passage 12 pointed- Ollf hereinafter. as is practicable. The porcelain insulator 11 is The invention accordingly consists in the feaa good di l tric, so that there is no leakage of tures of construction, combinations of elements, current thr u it, but as it readily condu 25 arrangements -of parts, and in the several steps h t, any heat generated by the resistance eleand,relation and order of each of said steps to e t 13 i quickly dissipated. i one or more of the others thereof, all as will be h tal end pieces 14-, 14 are rigi y c0 illustratively described herein, and the scope of meted t the r elain insulator rod 11. This the application of which will be indicated in the may be done by relating the rod and the proj e 30 following claims. ing ends of the resistance conductor 13 which is In referring to the drawing, the ms p a supported by the rod 11 to a suitable mold and s d end, and the like, a u d s y to molding the metal end pieces 14. 14 on said infacilitate the description, as the mounting of suiator rod 11, thereby completely embedding the the invention may be attached to any suitable resistance conductor 13, as is clearly shown in 35 apparatus in any desired Position I the Figure 2. Preferably the metal end pieces 14, 1s companying drawing in which is shown one of are of readily moldable metal, such as type various possible embodiments of the mechanical metal, which in cooling expands and firmly grips features Of'this invention- I the ends of the porcelain rod 11 so as to form 40 Figure 1 is an elevation of a single resistor befirm and rigid b d 40 fore mounting, Referring now particularly to Figures 2 and 3, Figure 2 is a longitudinal sectional view of the terminal conductors 5, 15, preferably in theresistor, form of pieces of bendable wire of high conduc- Figures is a cross sectional view, the section tivity which may be copper wire t d with being taken on the line Figure L tin are related to the moldfor molding the end 45 Figure :4 is plan View of a gang of resistors pieees 14 14 so that one end of each of said and the mounting therefor I conductors 15 is embedded in a molded metal Figure 5 is side elevation of a gang of reend piece 14. As is better shown in Figure 3,

eari i n ei ti gl e ga t i gg fg h gang of the end of the conductor 15 that is molded in sisters and t mounting theref the metal end piece 14 includes a port on 16 Figure 7 is a longitudinal sectional view through n Into anfluate Shape, and i P 1 3, pair of resistor gang units connected together, hon 16 15 o located m the metal plece the plane of the section corresponding to the line that e e is ance Conductor 13 1165 In the 06m 7'? of Figure 4, ter of the aforesaid arc. Preferably a further electrical union between these conductors is greatly improved, there being no noise created at this union when the resistor is placed in any audio circuit. I have further found that by shaping the conductor 15 as described, a better mechanical union between it and the molded metal end piece 14 results, and cold shots are substantially eliminated.

Referring now to Figures 8 and 9, I provide a suitable mold which is generally indicated by the numeral 18, and I relate a plurality of resistors 10 to this mold and mold around them -a supporting bar. As indicated in the accompanying drawing, the rod or bar 11 of each resistor 10 may be cylindrical, and in case itis, I preferably form therein an indenture 19, as best shown in Figures 1 and 2. When material is molded around such a resistor, some of it will enter the indenture 19 forming a tenon which will prevent rotation of the resistor. Such interlocking tenons and indentures, moreover, are efiective to prevent lateral movement of the resistors, which would otherwise be possible, even were the insulator rods 11 in the form of prisms.

The mold 18 preferably consists of a part 21 and a part 22. As shown in Figures 8 and 9, the part 22 has an elongated cavity 23 which, as shown, is substantially a parallelopiped, there being a recess 24 at one end of the cavity 23 for a purpose which will presently be described. One side of the cavity 23 extends to the parting line 26 between the parts 21 and 22 and merges into a cavity 25 which, as viewed in Figure 9, has the same area as the cavity 23, but a much smaller volume by reason of being shallower in 'width. The cavities 23 and 25 thus constitute,

when the parts 21 and 22 are together, a single chamber or cavity of parallelopipedal form.

In the sides of each of the parts 21 and 22, with their centers located along the parting line 26, are a plurality of semi-circular recesses 27 aligned to form a plurality of circular holes in each side of the mold 18, two pairs of recesses constituting two coaxial holes the diameters of which are the same as the diameters of the several insulator rods 11 of the resistors 10. The left hand boundary wall of the cavity 25 is so located with respect to the recesses 27 in the part 21 that the plane thereof secants the circles of said recesses, but partial cylindrical grooves 28 are formed in the said left hand wall in concentric relation with the recesses 27. A

I plurality of resistors 10 are related to the mold 18, with the insulator rods 11 located in the opposite holes constituted by the recesses 27 in the opposite parts 21 and 22, a substantial area of each insulator rod being covered by and in contact with the partial cylindrical surfaces 28 forming grooves in the left hand wall of the cavity 25. The resistors 10 are thus held in parallel formation, as is best shown in Figure 9, and with the indentures 19 located entirely within the combined cavity 23, 25.

One of the parts, for example the part 21,

at one end of the mounting for the resistors,

there is preferably provided an orifice of dove.-

tail shape 32 in the side of the part 22, and a core 33 of similar shape is'introduced into said orifice filling part of the cavity 23, as clearly shown in Figure 9. In order to form a longitudinal bore through the molded support, a rod 34 is introduced'into the cavity 23 extending between a hole in the core 32 and a hole 35 in the mold 18. In order to form holes in the support for the attachment thereof to any apparatus, a pair of rods 36, 36 extend through the cavities 23 and 25 from the part 21 to the part 22. It should be noted that the parting line 26 is displaced at the bottom of the mold l8 and passes through the center of the recess 24.

The resistors 10 having been located with respect to one of the parts 21 or 22, as.already set forth, the parts 21 and 22 having been joined togethei, the core 32 having been; inserted, and

the rods 34 and 36 having been placed in position, the parts 21 and 22 are secured together in any suitable manner, and plastic, molten or moldable material is introduced into the combined cavities 23 and 25. In some cases the upper end of said cavities, as it is viewed in Figures 8 and 9, may be open, and the material may be simply pouredthereinto; in other cases, the material may be forced into the cavities under pressure, the upper end thereof being closed except for a suitable orifice 38 for the introduction of the material under pressure and a vent hole 39. Preferably the material introduced into the mold is molten type metal, which solidifies quickly and expands on solidifying, firmly gripping the resistors 10. One advantage of using molten type metal is that the resulting bar is a conductor, and any one of the conductors 15 may be grounded thereon if desired. Other materials which might be introduced into the mold 18 are Bakelite or phenolic condensation product in plastic form, hard rubber, sealing wax, and, in fact, any substance which can be poured or molded under pressure.

In case Bakelite or other substance requiring baking is introduced into the mold 18, the mold is then heated to bake the material. In case type metal is used, it is found to have solidified in a relatively short time. When the substance in the mold 18 has become an integral solid, the parts 21 and 22 of the mold are separated, the rods 36 being first removed. It is then found that the resistors 10 are embedded in a bar 40 '(see Figure 5), which consists of a bottom portion 41 which filled the cavity 23, a top portion 42 which filled the cavity 25, and a tenon 43 which filled the cavity 24. The bar 40 may be readily removed from the cavity 23 in the part 22, the core 32 being broken in so doing, and when the core 32 is completely removed from the bar 40, there remains an indenture cavity 44 in the end of the bar opposite the tenon 43.

Referring now to Figure 7, the insulator rods 11 of the resistors 10 are firmly held between the portions 41 and 42 of the bar 40, and they are further held from lateral or rotative movement by tenon portions 45 fitting in the indentures 19, such tenon portions 45 having been made by substance flowing into the tenons 19. The upper central portions -of the insulator rods ll,

however, extend above theban 40, as shown in Figures 4 and 7.

Two or more bars 40 may be secured together,

as shown in Figure '7, by inserting the tenon 43 of one bar into the indenture 44 of the next bar.-

Each bar has a longitudinal bore 46 therethrough which remains after the rod 34 is removed. When the bars 40 are put together, the bores 46 are' aligned and a long rod 47 is passed through said bores. In this manner lateral displacement of one bar 40 with respect to the next bar 40 is prevented, the bars being interlocked together, and at the same time the bars are strengthened or reinforced, In accordance with certain features of the invention, the embedded rod 34 may be left in the bar 40, constituting a reinforcement thereof.

The removal of the rods 36 from the bars 40 leaves a plurality of vertical holes 48 in each bar by means of which they may be attached to any desired apparatus; The complete resistor gang units may be used singly or in multiple, and the conductors 15 thereof may be connected in any desired circuits. If desired, a plurality of conductors 15'on one side of a bar 40 may be connected together ,to connect certain resistors in parallel, and in case the bar 40 is of metal, it may be advantageously used as a ground for any number of conductors 15 which may be soldered thereto. Owing to the tenons and indentures 19, it is impossible for any resistor 10 to turn or to be moved laterally to ground a metal end piece 14 on the bar 41.

It will thus be seen that there has been provided by this invention a method and apparatus in which the various objects hereinabove set forth, together with many thoroughly practical advantages, are successfully achieved.

A-s various possible embodiments might be madeof the mechanical features of the above invention, and as the art herein descriLed might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter herein set forth, or shown in the accompanying drawing; is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the class described, in combination,-a plurality of resistors having an elongated ceramic insulating body, type metal end caps, and a type metal bar holding said resistors by said ceramic bodies.

2. In apparatus of the class described, in

- combination, a plurality of resistors having molded metallic end caps, and a molded bar spaced from said end caps holding said resistors of the same material as said end caps, said resistors being embedded in said bar. 4

-3. A resistor unit comprising an elongated body of insulating material, a resistance conductor in said body, molded metal end caps on the ends of said body, and a molded block emtion of a member and means positioned at the.

opposite ends of said block adapted to hold a spaces in each of said blocks in alignment sothat said member may he slipped therethrough to help support all of said blocks.

5. In resistor construction, in combination, a plurality of elongated resistor elements, a bar member in which portions of each of said elements are embedded, and means on said bar member and on said portions of said elements forming an interfit therebetween to prevent relative movement therebetween.

6. In resistor construction, in combination, a plurality of elongatedresistor elements substantially round in cross-section, a bar having a plurality of apertures within which said elements are disposed so that the opposite ends of said elements are substantially spaced from the longitudinal sides of said bar, and means in said bar and in the portions of said elements in engagement with said bar for forming an interfit therebetween to prevent rotation of said elements in said bar.

7. In resistor-construction, in combination, a plurality of elongated resistor elements substantially round in cross-section, a bar having a plurality of apertures within which said elements are disposed so that the opposite ends of said elements are substantially spaced from the longitudinal sides of said bar, and projections in said apertures interfitting with slots in said elements to form aninterfit therebetween.

8. In resistor construction, in combination, a plurality of elongated resistor units having conducting elements extending from their end por tions, and a bar having a series of apertures in which said elements are mounted, the end poraxes of said bar within each of said bars, each of said bars having a tenon formed at one end thereof and an indenture formed at the other end thereof so that said bars may be interlocked one with another, each of said bars having a hole extending therethrough substantially parallel to its longitudinal axis, the holes in each of said bars being in alignment when said bars are interlocked, and a reenforcing member extending through said holes in said bars.

10.. In resistor construction, in combination, a plurality of interlocking bars, a plurality of elongated resistor elements embedded cross-wise of the longitudinal axes of said bars within each of .said bars, and conducting partsextending from the opposite end portions of said elements. the end portions of said elements being spaced from the longitudinal sides of said bars.

11. In resistor construction, in combination, a holding bar having a plurality of slots formed in one side' thereof, the openings in said slots being smaller in width than the interior portions thereof, and a plurality of resistor elements having conductors extending from their opposite end portions, said resistor elements being dis- ,tions of said elements being substantially spaced posed cross-wise of the longitudinal axis of said bar in said slots and held therein by the top portions of said bar, the end portions of said elements being substantially spaced from the longintudinal sides of said bar.

holding bar having a plurality of slots formed in one side thereof, the openings in said slots being smaller in width than the interior portions thereof, a plurality of resistor elements having conductors extending from their opposite end portions, said resistor elements being disposed cross-wise of the longitudinal axis of said bar in said slots and held therein by the top portions of said bar, the end portions of said elements being substantially spaced from the longitudinal sides of said bar, and means disposed between said elements and the interiors of said slots adapted to form an interfit therebetween and prevent rotation of said elements.

13. In resistor construction, in combination, a plurality of resistor elements, a plurality of holding bars, said resistor elements being mounted cross-wise of the longitudinal axes 01 said bars in said holding bars and having their opposite end portions substantially spaced from the longitudinal sides of said bars, and means at the opposite ends of said bars for holding them together to form a single unit.

14. A resistor unit comprising an elongated body of insulating material, molded end caps on the ends of said body, an individual spacing and holding block of the same material as said molded end caps gripping said body of insulating material, a tenon at one end of said block, and an indenture at the other end of said block.

15. A resistor unit comprising an elongated body of insulating material, molded end caps on the ends of said body, and an individual spacing and holding block of the same material as said molded end caps grippin said body of insulating material.

16. An apparatus of the class described, in combination, a plurality of resistors, conductor means extending from the ends of said resistors,

and a molded bar spaced from said conductor means and holding said resistors, said resistors being embedded in said bar.

'17. An apparatus of the class described, in combination, a plurality of resistors, said resistors including conductors extending from the ends thereof, and a molded bar spaced from said conductors, said bar being of the same material as said conductors, said resistors being embedded in said bar.

MARCUS W. WEISCOPF. 

